The present invention relates to nursing bottles, more particularly, the type that utilize disposable liners, and the removal of air from the inside of these liners prior to feeding. Air that is trapped in a liner of a nursing bottle is often ingested by the baby feeding from the nursing bottle. This air ends up in the baby""s stomach and can cause pain and regurgitation. The elimination of the air from the liner prevents the baby from ingesting the air and so reduces the possibility of the negative side effects associated with air in the baby""s stomach.
The problem of air in a disposable liner of nursing bottles has been recognized for some time. The prior art disclose devices, which are used to eliminate air from the liner. For example, the prior art disclose the use of plungers, such as those disclosed in U.S. Pat. No. 5,524,783 to Popoff, and U.S. Pat. No. 4,880,125 to LeBleau. The end of the plunger is used to mechanically collapse the liner toward a nipple on the nursing bottles, which causes a decrease in volume of the liner. As the liquid in the liner moves upward in response to the mechanical pressure from the plunger, the air in the liner is expelled through the nipple. A similar device is disclosed in U.S. Pat. No. 4,176,745 to Miller that has a pneumatic member (12) that applies a force to a liner to expel air in the liner.
The problems with these devices are if the plunger or pneumatic member is removed, there is nothing to prevent the liner from re-expanding and air being reintroduced into the liner. When the air re-enters the liner, it must be collapsed again before the nursing bottle is used to feed an infant, and there is a separate accessory that must be carried with the bottle to expel the air.
Many nursing bottles use disposable liners. These liners provide for easy cleaning as they are simply thrown away after use and replaced. Many of these nursing bottles have apertures in the bottom to allow air into the bottle as the baby takes liquid from the nursing bottle. This allows the pressure around the liner to be equal to the pressure outside of the nursing bottle. An example of these types of nursing bottles is U.S. Pat. No. 2,846,103 to Maxwell.
The problem with these bottles is they don""t provide a means to remove the air trapped in the liner prior to feeding. Still other nursing bottles, such as Wiedemann, U.S. Pat. No. 5,687,861 and Randolph, U.S. Pat. No. 5,921,426 use liners and no valves. These bottles have a soft outer shell body that when hand pressure is applied to the container, the container collapses and direct contact is made with the liner exhausting air from the liner. The problem with these bottles is that when the liner has only a few ounces of fluid, an excessive amount of hand pressure must be applied, making it difficult to remove the air from the liner.
Accordingly, it is an object of the present invention to provide nursing bottles, especially intended for human infants or animals, which utilize air pressure to collapse a liner and expel air from the liner, e.g., expel air out of the liner via the nipple. More particularly, a nursing bottle having a rigid body, an open end, and an aperture, a flexible liner suspended from the open end of the body, a feeding nipple attachable to the open end of the body. An attached, slidably engagable, pump for pumping air into the chamber between the liner and body. The pump pressurizes the chamber and expels air from the liner. An air regulating means permits airflow in and out of the chamber in restricted quantity, so when pressure is applied to the pump, there is an increase of pressure within the chamber to force out the air trapped within the liner. The pump, also fashioned to be the protective storage hood for the nipple.
It is another object of the present invention to provide a nurser with an airflow regulating mean, the air regulating means being an orifice, or a course or passage through which air may move or be directed between close fitting parts. When pressure is applied to the pump, air escapes through the air regulating means, however there is sufficient pressure to expel air from the liner. When the pump is drawn out of the body, air enters the chamber through the same air regulating means, so the pump can be pumped again. The airflow regulating means is designed to be less restrictive than the orifice of the nipple so that air does not readily reenter the liner. In another embodiment, the slidable pump, pumps air through a valve to pressurize the air in the chamber and expel air from the liner.
It is another object of the present invention to provide nursing bottles that promotes upright feeding by keeping the nipple full of liquid during feeding.
It is another object of the present invention to provide nursing bottles that are easy to use and operate.
It is a further object of the present invention to provide nursing bottles that are easy to remove air from the liner prior to feeding.
It is a further object of the present invention to provide nursing bottles that are economically and easily manufactured for widespread sale and use.